You saw it yourself in black and white, albeit the grainy black and white of an amateurishly shot video, and like many, you perhaps thought you were seeing a clear-cut case of police brutality.

But 12 jurors also saw that video, and their reaction was to acquit the officers taped as they surrounded and clubbed Rodney King.

How could a video have one effect on the so-called jury of public opinion and an apparently different one with the actual jury in the Simi Valley courtroom?

"They didn't see the same video you saw," said Harvey Weitz, a New York-based attorney who analyzed the Rodney King case for the Courtroom TV network. "You saw a real-time video that went on for 81 seconds. The jury saw an 81-second video that was broken down frame by frame and dissected minutely by experts. They got, 'Here's frame 163,' rather [than] seeing the totality of it. It distorted the actual event."

The now-famous video, shot by an amateur from a balcony overlooking the beating scene, was expected to weigh heavily for the prosecution's case against the officers, but was neutralized by the defense, several legal observers said.

"What it did was shift the focus from the brutality of the event to an analysis of 'Was [Mr. King] reaching into his pocket for a gun?' " said Mr. Weitz, who frequently handles cases of alleged police brutality.

Videos have long been used in criminal cases -- in bank robberies, for example, in which a camera has captured the action. The result of the video's use in the King case, however, may make lawyers think differently about how such evidence can best be presented in future criminal trials, lawyers said.

"Any time you have video, you're going to grab it and use it, but now, I think what lawyers have learned is that if you show it often . . . [jurors] start to look at it in a more clinical sense," said Greta Van Susteren, a Washington lawyer who teaches at Georgetown and analyzes legal issues for CNN. "I've seen the video myself maybe 10 times, and it's horrifying, but I react differently to it now than when I first saw it."

She and other lawyers expressed shock that the video didn't contribute to a guilty verdict for the officers on trial, and noted that other factors such as the change in venue and the make-up of the jury -- which had no black members -- ultimately played into the decision.

"I kept thinking, if you can't convict police officers with this videotape, what hope do you have without a videotape?" said Yale Kamisar, a professor of criminal law at the University of Michigan. "With this case, it's clear that the video is not all-powerful. It's still powerful, but it met up against the more powerful force of 'Our police officers, right or wrong.' "

The Rodney King case is not the first in which a seemingly devastating videotape failed to convict a defendant.

* In 1990, a District of Columbia jury deadlocked over a drug charge against then-Mayor Marion S. Barry Jr., even though the jury was shown an FBI videotape of Barry smoking crack cocaine in a hotel room. He was convicted of a separate drug charge.

* Earlier this year, a jury in Detroit found a black woman not guilty of assault in the videotaped beating of a white woman at a fireworks show. Cassandra Rutherford, 18, was the only one of a half-dozen black women facing charges to go to trial in the racially charged incident because the others pleaded no contest after learning that they had been videotaped by a bystander.

In the trial of the Los Angeles police officers, jurors repeatedly saw the beating video during the proceedings themselves and watched it again, occasionally in slow motion or stop-action, during their closed-door deliberations.

"A video like that should have been very effective," said Abraham Dash, a law professor at the University of Maryland and a former prosecutor. "Those pictures show that guy being beaten to a pulp. The defense, though, showed it frame by frame to show how [Officer Laurence Powell] was scared because King wouldn't submit. It helped them show the jury the officers were not able to force him into submission."

The repeated viewings of the video probably served to lessen its impact, a psychologist said.

"It's the whole issue of desensitization from repeated viewings," said Aletha Huston, a psychologist at the University of Kansas who studies the ways violence on television affects viewers. "Human beings, when they see something shocking, after repeated exposure it gets less shocking. It's a means of survival. You can't keep being emotionally overwhelmed like that."

Mark Crispin Miller, a professor at the Johns Hopkins University who comments on the media, said manipulation of the original video -- slowing it down, stopping the action -- served to change its very nature.

"What it does in this case is it took what was, in fact, a brutal spree and it made it look like a careful, methodical, casebook subjugation of a suspect," said Mr. Miller.

Mr. Miller said the verdict shows that while a videotape may seem an indisputable record of an event, it can still be mitigated by both the viewers' preconceived notions and by the points that a skilled commentator wants to make.

"On the one hand, videotaped images are usually a lot more powerful than any voice-over that may accompany it, but at the same time, any kind of commentary that skillful can make some people think they're seeing something else," Mr. Miller said. "The people in Simi Valley, they're inclined to respect police officers. They're their neighbors. They were ripe for a certain kind of persuasion by the defense attorneys."

Mr. Weitz said the prosecution should have objected more strenuously to the defense tactic of bringing in experts to interpret the videotape. That shifted the focus from what the jurors were seeing with their own eyes to what the experts told them they were seeing, he said.

"The jurors think, 'If the experts can't agree, how can we convict beyond a reasonable doubt?' " Mr. Weitz said.